Sickle Cell Anemia Inheritance Patterns

Procedure
1. Place 25 red (S) and 25 blue (s) beads into the 100 mL beaker and mix well.
2. Randomly (without looking) remove two beads. Repeat 10 times (without returning the beads to the beaker), each time recording if it was a SS, Ss or ss.

3. Assume that each individual with the ss genotype passed away, and remove ss instances from the population.
4. The remaining beads survived and reproduced.
5. Count how many red and blue beads remained (separately) and place twice that number back in the beaker.
6. Repeat the process seven times.

Post-Lab Questions
1. What is the remaining ratio of alleles?

2. Have any been selected against?

3. Given enough generations, would you expect one of these alleles to completely disappear from the population?
Why or why not?

4. Would this be different if you started with a larger population? Smaller?

5. After hundreds or even thousands of generations both alleles are still common in those of African Ancestry.
How would you explain this?

6. The worldwide distribution of sickle gene matches very closely to the worldwide distribution of Malaria.
1. (http://www.cdc.gov/malaria/distribution_epi/distribution.htm) Is this significant? Why or why not?